<sarcasm>It must be operator error. Briansquib shoots motorsports with his 5DII and the AF performs flawlessly, tracking fast-moving carts around curves, even moving toward and and away from the camera. If you can't even shoot a running kid, don't blame the camera.</sarcasm>
Yes, I know from experience that the 5DII's AF is pretty bad with anything moving. That's the main reason I plan to get a 1D X as soon as they're available.
<insult> removed <insult>
Just because you cant run 100m in <11 sec doesn't mean no one else can
Thanks for the kind insult. The <sarcasm> was not directed at you, but rather at awinphoto - I wanted to be absolutely clear that I was not insulting his technique or skill, in the case of shooting kids playing. As Orangutan correctly stated, that's a challenging situation for AF, and IMO the 5DII is quite bad at it, relative to the 7D for example.
I've certainly acknowledged that your photos of moving subjects with the 5DII are excellent, but I still don't believe that they're relvant or proving your points - the panning shot of the train being a great example of the fact that it's not the camera responsible for keeping the subject in focus, it's the skill of the photographer. You
are following the train, that's what panning
means. Furthermore, it's at a distance and at f/11 - your AF could have been off by many yards and the subject would still be in focus. The 5DII's AF isn't doing the job. Like several of the go cart examples, they highlight your
ample skill, but do not convincingly demonstrate the capability (or lack thereof) of the 5DII's AF system.
The simple fact is that if I put a fast-focusing lens like the 70-200mm f/2.8L IS II on the 5DII, put it in AI Servo, set it to f/2.8 and put the center AF point over one of my kids running around the yard and start tracking and shooting, my keeper rate is pretty low. If I put the same lens on the 7D in AI Servo, the keeper rate is close to 100%, despite taking 2x as many shots with the faster frame rate.
Just for the doubters - here is a panned train on a 5D at 1/25, f11, iso50
So, this thread is about how the IQ of the 7D is bad at low ISO. Just for the doubters, here is an ISO 100 shot from the 7D:
Now, does that show that the 7D has no noise at low ISO? Sure, it does - just about as convincingly as your panning shots demonstrate the effectiveness of the 5DII's AF.